import java.util.*;

/**
 * @Author YuanYuan
 * @Date 2022/5/10
 * @Time 11:51
 */
public class TestDemo {
    public static void main(String[] args){
        Scanner scanner = new Scanner(System.in);
        while(scanner.hasNextLine()) {
            String str = scanner.nextLine();
            HashMap<Character, Integer> hashtable = new HashMap<Character,Integer>();
            for(int i = 0;i<str.length();i++) {
                if(!hashtable.containsKey(str.charAt(i))){
                    System.out.print(str.charAt(i));
                    hashtable.put(str.charAt(i),i);
                }
            }
            System.out.println();
        }
    }
}
